Unit 1 of 5
Study guide for CLEP CLEP Chemistry — Unit 1: Atomic Structure and Periodicity. Practice questions, key concepts, and exam tips.
96
Practice Questions
40
Flashcards
5
Key Topics
Try these 5 questions from this unit. Sign up for full access to all 96.
What is the primary factor that determines the ionization energy of an electron in a particular subshell of an atom?
The mass of the nucleus
The number of electrons in the subshell
The type of orbital occupied by the electron
The distance of the subshell from the nucleus
The spin of the electron in the subshell
Answer: D — Ionization energy is related to the distance from the nucleus and the effective charge of the nucleus, as described by Coulomb's law.
What is the primary reason that elements in the same group of the periodic table exhibit similar chemical properties?
They have the same atomic mass
They have the same number of valence electrons
They have the same number of protons in the nucleus
They have the same number of electron shells
They have the same number of electrons in the innermost shell
Answer: B — Elements in the same group have similar chemical properties due to the same number of valence electrons, which determines their reactivity.
A sample of boron has two naturally occurring isotopes: boron-10 with a mass of 10.013 u and a relative abundance of 19.1%, and boron-11 with a mass of 11.009 u and a relative abundance of 80.9%. What is the average atomic mass of boron?
9.91 u
10.81 u
11.01 u
10.45 u
10.98 u
Answer: B — To calculate the average atomic mass, multiply the mass of each isotope by its relative abundance and sum the results: (10.013 u * 0.191) + (11.009 u * 0.809) = 10.81 u
What is the principal quantum number of the outermost energy level of a sodium atom?
1
2
3
4
5
Answer: C — 3 is correct because the outermost energy level of a sodium atom is the third energy level, since sodium has 11 electrons and its electron configuration is 1s²2s²2p⁶3s¹.
A chemist is studying the properties of a newly discovered compound. The chemist creates a model of the compound, including its molecular structure and electron configuration. Which of the following best describes the purpose of creating this model?
To determine the exact molecular weight of the compound
To identify the chemical properties of the compound at the macroscopic level
To develop a new method for synthesizing the compound
To confirm the compound's reactivity with other known substances
To visualize the particulate-level properties of the compound and make predictions about its behavior
Answer: E — The model helps the chemist understand the compound's properties at the particulate level, making predictions about its behavior.
Start with your full diagnostic, projected score, study plan and analytics, one full mock, plus 5 practice questions per course — each fully explained, no credit card required. Paid plans add unlimited practice, unlimited mock exams, and Sage.
CLEP® is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this product.